In this PETC framework, the one referring to [1]} involves only population and environment. Population growth exerts pressure on the environment, and failure to provide adequate resources from the environment acts as a positive check on population through higher mortality (Figure REF a). Technology does not play a role in this simplest Malthusian modelMalthus considered the increase of carrying capacity by autonomously occurring inventions [2]}, however, this was not discussed by [3]} in her model intercomparison.. Culture in the form of preventive checks—such as birth control—acts on population only in later versions of his theory [4]}. At its core remains “the dependent role he assigns to population growth” [5]}. D. [6]} proposed that the incentive to intensify and develop technologies comes from a stimulus in population pressure. The demand for more land (\(E\) ), however, leads to declining marginal benefits of and a negative feedback on innovation (\(T\) ) due to high costs of renting the land (Figure REF b). In Ricardo's work, population is independent, and technology and environment are the dependent variables.
